Running DOOM And Super Mario 64 Inside A PDF File

Although generally described as a document format, PDFs have ballooned from a Postscript-lite format into a mutant featuring XML and JavaScript support, basically turning what once was a fairly simple format into an interactive page. Naturally, this has to be used for good, and that is why we have the Doom PDF project, as well as [Game of Tobi] using that project as the inspiration for a Super Mario 64 port based on the decompiled source code.

The nice thing about the Super Mario 64 version is that it’s stand-alone, running from a 23.5 MB PDF, unlike the Doom PDF which runs the game in DOSBox. The compromise is that Super Mario 64 PDF runs at just a few FPS, with the output in glorious ASCII.

What enables this feat is to open the PDF in a viewer that supports JavaScript, with the PDF.js that comes with most browsers generally allowing for integrated JS in the PDF to be executed. Unfortunately [Game of Tobi] hasn’t released source code for this project, but we hope that this is forthcoming.

While one can argue about the practicality of this whole demonstration from a gaming perspective, it definitely shows that PDF as a format has gotten way out of hand now that it’s even overrun with hellspawn and Italian plumbers.

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An Event Badge Re-Imagined As A Cyberdeck

We’re used to handheld Linux devices of varying usefulness appearing on a regular basis, but there’s something about the one in a video from [Rootkit Labs] which sets it aside from the herd. It’s a fork of a conference badge.

The WHY2025 badge had pretty capable hardware, with an ESP32-P4, a really nice screen, and the lovely SolderParty keyboard. Here it’s been forked, to become a carrier board for their previous project, the Flipper Blackhat. This is a Linux add-on for the Flipepr Zero, and it seems that plenty of people wanted it in a more useful context. The result is something that looks a lot like a WHY badge, but running Linux.

It’s a great shame when badges end up lying unused after the event, and ones like the WHY 2025 badge are a serious effort to make something that endures. Here, the badge endures in spirit by being forked and re-engineered, and we like it a lot. The full video is below the break.

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CPU Scheduler Divines The Will Of The Heavens

Horoscopes are a great way to pass a boring lunchbreak, and an excellent excuse for ending a ill-considered relationship. They’re also a hilarious way to handle CPU scheduling under Linux, thanks to the work of [Lucas Zampieri].

The project is called scx_horoscope, and it’s a sched_Ext scheduler that makes its CPU scheduling choices based on what the heavens are doing in real time. Different tasks are handled based on different astronomical objects. For example, the Sun represents life force, and thus grants boons to key system processes. The Moon, an emotive influence, rules over interactive processes like shells and terminals. Mercury, as the god of communication, handles network and IO tasks, and so it goes from there. It’s not just a surface level thing, either—[Lucas] has implemented the influences of the elements of fire, air, earth, and water, and there are negative timeslice penalties on associated tasks when a given planet lands in retrograde.

You can argue whether or not the broader motions of the heavens have any impact on our lives based on the time and circumstances of our birth. But you can’t argue that scx_horoscope really will influence how your computer runs based on the dance of the planets in the sky. Mostly, though, we concern ourselves with astronomy rather than astrology around these parts!

[Thanks to Benjamin for the tip!]

Fixing Sony And Philips’ Doomed CD-i Console

Although not intended to be a game console, the CD-i would see a a couple of games released for it that would cement its position in gaming history as the butt of countless jokes, some of which still make Nintendo upset to this day. That aside, it’s still a fascinating glimpse at the CD-based multimedia future envisioned in the early 90s, starting with its release in 1990. Recently [MattKC] decided to purchase another CD-i in a fit of nostalgic rage, and repair it to show the world what the future could have been like.

Although Sony and Philips co-developed the device, Sony would go on to release the PlayStation a few years later, which made the CD-i’s life and expectations for it that much harder, leading to it slowly fading into history. The Magnavox one that [MattKC] got is one of the later models, based on the CD-i 450 that was introduced in 1994 as one of the more gaming-oriented models.

As is typical with older devices that use optical media, it would not read discs. It also would sometimes boot up with a ‘Memory Full’ error. This is a common fault due to the built-in battery having run out, erasing RAM-stored values and causing random glitches like this when garbage values were read in on boot.

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Hackaday Links: February 1, 2026

For many readers, more snow is the last thing they want to see right now…but what if it comes in the form of an online simulator in the style of an old DOS game? Created by [Potch], it works like one of those “falling sand” simulators, with sliders that let you control various elements of the wintry action. For more a immersive experience, open the window and let some cold air in while you play.

If those old school graphics have you yearning for a simpler time, then you’ll love Places to Telnet, a page on the very slick CRT-themed telnet.org that lists servers you can connect to. The list is made up primarily of games, but there’s also systems you can call up to do things like show the weather or browse Wikipedia. They even take submissions, so if you know any interesting destinations that aren’t on the list, make sure to share with the class.

Our ability to make and use tools is one of the things that separates us from the rest of the animal kingdom, and is an ability not often seen outside of primates. But a recent paper in Current Biology describes how one cow, Veronika, has been observed using a long-handled brush to scratch herself. Apparently the clever heifer will even flip the brush around and use the handle side when she wants to really dig in there. The paper says the findings “invite a reassessment of livestock cognition”, and points out that little serious research has been done on bovine intelligence in the 10,000 or so years since humans first domesticated them. We’re just happy this paper came out when it did — that way it will be a distant memory by the time we fire up the grill in the summer.

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A small plastic object can be seen in front of the tip of a hypodermic needle. The object is made of clear, slightly purple-tinted plastic. It is roughly circular, with edges thicker than the center.

The Latest From RepRapMicron – Nail Gel, First Objects, And More

We’ve been following [Vik Olliver]’s progress on the μRepRap project with interest for some time now. The project’s goal is to build a 3D printer that can print feature sizes down to about 10 microns – the same feature size used in the Intel 4004 processor. At the recent Everything Open 2026 conference, [Vik] presented an overview of all the progress he’s made in the last year, including printer improvements, material woes, and the first multi-layer prints (presentation slides).

The motion stage has undergone some fundamental improvements recently. The original XY motion table was supported on four flexures which allowed movement in X and Y, but also introduced slight variations in Z – obviously a problem in a system that needs to be accurate down to the microns. The latest version now uses complementary flexures to maintain a constant Z height, and eliminates interference between the X and Y axes. The axis motion drivers were also redesigned with parallel-bar linear reducers inspired by a pantograph, increasing their usable range from two to eight millimeters.

Rather than extruding material, the μRepRap uses an electrochemically-etched needle point to deposit UV-curable gel on the build surface. [Vik] found that a bit of nitric acid in the needle etching solution gave the edges of the probe a bit of a rough texture which let it hold more resin. He started his test prints using normal 3D printer resin, but it turns out that dissolved oxygen inhibits curing – quite a problem for small, air-exposed droplets. Fortuitously, UV nail gel does cure in air, and the next set of tests were printed in nail gel, including the first layered prints (one of which can be seen above, on top of a hypodermic needle). The μRepRap can’t yet print large numbers of layers, but [Vik] did print some hinged parts that could be folded into shape.

There’s much more in the presentation than can be covered here, including some interesting thoughts about the possibility of 3D printing electrochemical memory cells in ionic gel. Near the end of the presentation, [Vik] listed some pieces of related work, including necroprinting and this homemade micro-manipulator.

 

A DIY Headset For SteamVR

The modern era of VR started a long time ago, and a wide range of commercial headsets have proliferated on the market since then. If you don’t want to buy off the shelf, though, you could always follow [Manolo]’s example and build your own.

This DIY headset is known as the Persephone 3 Lite, and is intended for use with SteamVR.  It’s got the requisite motion tracking thanks to a Raspberry Pi Pico, paired with an MPU6500 inertial measurement unit. As for the optics, the headset relies on a pair of 2.9-inch square displays that operate at a resolution of 1440 x 1440 with a refresh rate up to 90 Hz. They’re paired with cheap Fresnel lenses sourced from Aliexpress for a few dollars. Everything is wrapped up in a custom 3D-printed housing that holds all the relevant pieces in the right place so that your eyes can focus on both screens at once. The head strap is perhaps the only off-the-shelf piece, sourced from a Quest 2 device.

If you’re eager to recreate this build at home, files are available over on [Manolo’s] Patreon page for subscribers. We’ve featured some other DIY headset builds before, too. Video after the break.

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